Thank you for reaching out to us! I appreciate you providing us with the browser your using. I'm sorry that the preview function isn't working as it usually does! If the sake of troubleshooting, would you be able to try the same process in Google Chrome or Firefox? IE isn't always as compatible with how Constant Contact functions as a web-based system. Thank you for your time!
We apologize for any inconvenience this may cause, but it looks like this is a known issue that we are having with our Custom Code emails. We let the a proper teams know that you are experiencing this issue and they are working on getting it fixed as soon as possible. Again, we do apologize for any inconvenience this may have caused you.